Q1) The table given below shows joint probability distribution of X and Y. Determine the covariance between the X and Y?
|
|
|
X
|
|
|
|
0
|
1
|
2
|
|
0
|
0.13
|
0.08
|
0.021
|
Y
|
1
|
0.16
|
0.14
|
0.03
|
|
2
|
0.07
|
0.04
|
0.13
|
a) 0.29
b) 0.23
c) 0.25
d) 0.21
Q2) Probability a person catches cold in the cold and flu season is 0.4. Suppose that 10 people are selected at random.
i) Determine the probability that exactly four of them will catch cold?
a) 0.751
b) 0.502
c) 0.242
d) 0.251
ii) Determine the probability that 4 or more of them will catch a cold?
a) 0.715
b) 0.618
c) 0.546
d) 0.312
iii) On average, how many of these 10 people would you expect to catch cold?
a) 4
b) 3
c) 2
d) 1
iv) Compute the standard deviation for number of people catching a cold?
a) 1.245
b) 1.265
c) 1.549
d) 1.125